GREEN BAY – The Green Bay Packers training staff has itself a new fancy-schmancy treadmill that allows players to run without their legs and feet bearing their full body weight. It’s come in handy for injured running back Cedric Benson, who’s on injured reserve with the designation to return with a Lisfranc foot sprain suffered Oct. 7 at Indianapolis.

“I’ve been doing that at about 65 percent body weight,” Benson said Friday, adding that he’d also done a speed ladder drill with his full weight.

That 65 percent might be roughly the percentage Benson is back to full health as well. While he’s not ready – or eligible – to play in Sunday’s game at Detroit, he’s hopeful to be back on the field for the team’s Dec. 9 game against the Lions at home.

According to the NFL’s new IR rule, players designated for return cannot practice for six weeks and cannot play for eight. Benson would be eligible to return to practice next week – he’s not required to do so and may not be ready to do so, but he could do so – and would be eligible to play against the Lions after sitting out this week, next week’s game at the New York Giants and the Dec. 2 home game against Minnesota.

“Cedric had the opportunity to have some testing done (recently) and everything’s positive. His rehab has picked up,” Packers coach Mike McCarthy said after practice Friday. “We’ll see where we are next week. We don’t have a startup date exactly when he’s going to be ready. (But) we had some good news in the past seven days.”

Ideally, Benson would like to play against the Lions on Dec. 9 because the next week’s game is, well, somewhat important to him.

“I’m kind of looking and thinking the Bears game,” he said with a smile, referring to the Dec. 16 game at Soldier Field against the team that drafted him in 2005.

“I think we’re still a little bit out from practicing, from putting on a cleat and pounding on it like that. I think we’re still a couple of weeks away from that, but very close, very close. Kind of the way the doctor puts it to me all the time is regardless of anything, whether you could play tomorrow, you’ve still got three weeks where you can’t play.”

Benson wouldn’t put a timeline on his return – “I’m very confident about saying I’ll be back before the season’s over,” was all he’d say – and is wary about trying to come back prematurely.

“I think if I come back early, if I try to rush it, it can really affect me,” Benson said. “So I think it’s in my best interest as the team’s as well and my contribution to the team to come back when it’s ready to come back.”

But Benson is thankful for the rule change that will allow him to play again this year. Previously, players placed on IR were done for the year, end of story.

“If this was last year, I wouldn’t have the opportunity to come back. So it is a good thing,” Benson said. “It’s tough, and considering where we were progressing to and where we were when things did happen and sidelined us for a while, it’s tough to deal with. I was going up and down with, should we have surgery? Let’s wait and see what the foot tells us, what the X-rays — we take several X-rays as we go about this process — and I was struggling a little bit with (that), because naturally when every player gets hurt he wants to come back as fast as he can.”

Benson, who had rushed 71 times for 248 yards and caught 14 passes for 97 yards in five games, admitted that it took him a week of regular-season action to get up to speed after signing midway through training camp. After rushing nine times for just 18 yards against San Francisco, he put up 81 yards against the Bears in Week 2 and 84 yards against New Orleans in Week 4. He can’t afford any lag time in getting back into the swing of things with so few games left.

“You know, I’ve thought about that. Naturally, to get (up to) game speed, you need a game or two just to get the feel and the flow and the rhythm. That’s kind of what I ran into when I first got here with Week 1 and a couple preseason games,” Benson said. “But I don’t want that to be a factor, and I’m going to try my best for it not to be. It’s almost one of those deals that is inevitable. You need a game or two, but I’m going to try my best to already be up to speed.”

To that end, Benson has tried to make the most of his time on the sideline, maximizing his study time of the playbook and attending installation meetings even though he’s not part of each week’s game plan.

“I’ve had endless amounts of playbooks and films that they provide for us, I’m sitting in the installation meetings, things like that. And as I get stronger on my foot, I’ll tend more to the meetings and things like that to be up to date on each game plan each week,” Benson said. “So I feel very strong about the playbook and all that. I think coming back, I think that obstacle will be eliminated.”